Seedbed density

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Seedbed density

• David South
• Auburn University

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In the old days, high seedbed densities were
recommended
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Wakeley - 1935

• Species Final density/square foot
• Longleaf 25- 35
• Slash 35-45
• Loblolly 40-50
• Shortleaf 55-70

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One nurseryman in SC produces unusually Good
longleaf pine seedlings at a density Of
approximately 40 per square foot. (Wakeley 1935)
Civilian Conservation Corps At the left,
different stages of seedbed preparation may be
seen. In the Center men are hand sowing longleaf
seeds. On the right, men are laying down
burlap bags as a mulch. Kisatchie National
Forests, Louisiana. Photo taken by J.D. Nellis
1934. Credit Line U.S. Forest Service. (photo
287379)
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Due to small seedling size, many plantations of
longleaf failed Because they took so long to
emerge from the grass stage. In this plantation,
8 rows of longleaf are flanked by slash
pine. Survival of both species was about
80. Some longleaf began emerging from grass
stage 4 years after planting.
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Today

• Species Final density/square foot
• Longleaf 6-8
• Slash 15
• Loblolly 15
• Shortleaf 20

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High seedbed densities small seedlings
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Shoot/root ratio root/shoot ratioor root/weight
ratio?
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High seedbed densities small seedlings
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High seedbed densities small seedlings
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High seedbed densities small seedlings
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High seedbed densities small seedlings
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High seedbed densities small seedlings
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High seedbed densities low root-weight ratios
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High seedbed densities low root-shoot ratios
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High seedbed densities high culls and low seed
efficiency
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Bigger trees? Or just fewer small trees?
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High seedbed densities low quality hardwood
seedlings
Stoeckeler 1967 USFS Res. Note NC-25
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Better growth after outplanting
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Past target seedling

• Seedbed density 28/ft2
• Nitrogen 150 lbs/ac
• Avg RCD 4 mm
• Avg ht 10 in
• 80 grade 2 seedlings

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Future Optimum Seedling

• Seedbed density 20/ft2
• Nitrogen 375 lbs/ac
• Avg RCD 8.5 mm
• Avg ht 15 in
• 100 grade 1 seedlings